Company Expects Randomization to be Completed by End of 2018 and Anticipates Release of Top-line Data in Q4 2019

WALTHAM, Mass., June 14, 2018 (GLOBE NEWSWIRE) — Chiasma, Inc. (Nasdaq:CHMA), a clinical-stage biopharmaceutical company focused on improving the lives of patients with rare and serious chronic diseases, today announced it has achieved 50% patients randomized in its international Phase 3 clinical trial, referred to as “CHIASMA OPTIMAL” (Octreotide capsules vs. Placebo Treatment In MultinationAL centers), of its octreotide capsules product candidate, conditionally trade-named MYCAPSSA®, for the maintenance therapy of adult patients with acromegaly. The Company also announced CHIASMA OPTIMAL has achieved the FDA-required minimum of 10 patients randomized from the United States.

Chiasma expects CHIASMA OPTIMAL to complete randomization by the end of 2018 and anticipates the release of top-line data from this trial in Q4 2019. This timing is consistent with the plans Chiasma announced at the initiation of the trial.

The CHIASMA OPTIMAL trial is being conducted under a Special Protocol Assessment (SPA) with the U.S. Food and Drug Administration (FDA)’s Division of Metabolism and Endocrinology Products. A SPA is a process by which an applicant and the FDA reach an agreement on the protocol design, endpoints and analysis of a Phase 3 clinical trial prior to initiation, in order to determine if the trial adequately addresses scientific and regulatory requirements for FDA approval.

“We are encouraged by the clinical progress in our acromegaly program,” said Mark Fitzpatrick, president and CEO of Chiasma. “Reaching the midway point for randomization in our CHIASMA OPTIMAL Phase 3 trial is an important step toward our goal of resubmitting a New Drug Application with the FDA. This enrollment milestone demonstrates the tangible progress we are making toward advancing octreotide capsules as a maintenance treatment for adult acromegaly patients. We strongly believe in MYCAPSSA as a potential new treatment option for adult patients with acromegaly.”

Octreotide capsules are an investigational new oral drug proposed for the maintenance therapy of adult patients with acromegaly. Acromegaly is most commonly caused by a benign tumor of the pituitary gland that produces excess growth hormone (GH), ultimately leading to significant health problems and early death if untreated. GH regulates multiple metabolic processes and stimulates the production of insulin-like growth factor 1 (IGF-1) in the liver, which stimulates the growth of bones and other tissues. If approved, octreotide capsules would be the first oral somatostatin analog treatment option available for acromegaly patients, where the current standard of care is somatostatin analog injections.

CHIASMA OPTIMAL Phase 3 Trial

CHIASMA OPTIMAL is a randomized, double-blind, placebo-controlled, nine-month clinical trial in 50 adult acromegaly patients (at least 20% of whom must be recruited from the United States) whose disease is biochemically controlled, based upon levels of IGF-1, a byproduct of increased GH levels caused by acromegaly, on injectable somatostatin analogs at baseline (average IGF-1 ≤ 1.0 × upper limit of normal (ULN)). The patients also must have confirmed active acromegaly following their last surgical intervention based upon an elevated IGF-1 at that time of ≥ 1.3 × ULN. The trial is being randomized on a 1:1 basis to octreotide capsules or placebo. Patients are being dose titrated from 40 mg per day to up to a maximum of 80 mg per day, equaling two capsules in the morning and two capsules in the evening. Patients meeting predefined biochemical failure criteria in either treatment arm during the course of the trial will be considered treatment failures and revert to their original treatment of injections and will be monitored for the remainder of the trial. The primary endpoint of the trial is the proportion of patients who maintain their biochemical response compared to placebo at the end of the nine-month, double-blind, placebo-controlled period as measured using the average of the last two IGF-1 levels ≤ 1.0 × ULN. Chiasma continues to anticipate more than 50 clinical sites will be dedicated to CHIASMA OPTIMAL. Chiasma now expects the trial to complete randomization by the end of 2018 and anticipates the release of top-line data from this Phase 3 clinical trial in Q4 2019.

About Chiasma Chiasma is focused on improving the lives of patients who face challenges associated with their existing treatments for rare and serious chronic diseases. Employing its Transient Permeability Enhancer (TPE®) technology platform, Chiasma seeks to develop oral medications that are currently available only as injections. In September 2017, the Company initiated CHIASMA OPTIMAL, its third Phase 3 clinical trial for its octreotide capsules product candidate, conditionally trade-named MYCAPSSA®, for the maintenance therapy of adult patients with acromegaly in whom prior treatment with somatostatin analogs has been shown to be effective and tolerated following agreement with the FDA on the design of the trial. Chiasma is headquartered in Waltham, MA with a wholly owned subsidiary in Israel. MYCAPSSA, TPE and CHIASMA are registered trademarks of Chiasma. For more information, please visit the Company’s website at www.chiasma.com.

Forward-Looking Statements This release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the Company’s development of octreotide capsules, conditionally named MYCAPSSA, for the treatment of acromegaly, the Company’s efforts to potentially obtain regulatory approval in the United States by conducting the Phase 3 CHIASMA OPTIMAL clinical trial under a Special Protocol Assessment, the number of clinical sites that will be dedicated to the CHIASMA OPTIMAL clinical trial, the timing of receipt and announcement of top-line and other clinical data and submission of regulatory filings, including the Company’s ability to complete enrollment in the CHIASMA OPTIMAL trial by the end of 2018, and its ability to release top-line data from the CHIASMA OPTIMAL trial in Q4 2019. Any forward-looking statements in this press release are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with the regulatory review and approval process generally; risks associated with Chiasma’s MPOWERED Phase 3 clinical trial to support regulatory approval of octreotide capsules in the E.U.; risks associated with Chiasma conducting the additional randomized, double-blind and controlled Phase 3 CHIASMA OPTIMAL clinical trial to support regulatory approval of octreotide capsules in the United States, including risks related to the enrollment, timing and associated expenses; risks associated with patient enrollment and variability in the number and types of patients available for clinical trials, which is particularly challenging for orphan indications, and the risk that the CHIASMA OPTIMAL trial may be particularly difficult to enroll given the placebo-controlled design as well as other ongoing clinical trials in adult acromegaly patients; risks associated with Special Protocol Assessment agreements, including the risk that Special Protocol Assessment agreements are not a guarantee of approval and the FDA may not approve octreotide capsules even if the Phase 3 trial is successful; risks associated with the ability of the Company’s suppliers to pass future regulatory inspections; risks associated with obtaining, maintaining and protecting intellectual property; the risk of competition from currently approved therapies and from other companies developing products for similar uses; risks associated with Chiasma’s financial position, including its ability to manage operating expenses and/or obtain additional funding to support its business activities; risks associated with Chiasma’s dependence on third parties; and risks associated with defending any litigation, including the risk that we incur more costs than we expect and uncertainty involving the outcome. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section entitled “Risk Factors” in Chiasma’s Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission (SEC) on March 20, 2018, and in subsequent filings with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and Chiasma undertakes no duty to update this information unless required by law.